Loose leaf binder mechanism



Jlgvne 13, 1933. J, C, DAWSON 1,913,700

LOOSE LEAF BINDER MECHAN ISM lFiled May 31, 1930 i Patented June 173, 1933 UNiTi-:D STATES viniTizivTori-fici;

JAMES o. DAWSON, OF WEBSTER. GROVES, Missouni, `llissrenon "ro ELMA n. DAWSON, y c OF WEBSTER enovnsmssoum i c u "LOOSE `LEAF BrNDEaMEoHANTsia Application ined May 31,01930. serial 100,453,445;

This invention relates to improvements in loose leaf binder mechanism.

The objects of the present invention are to provide means to secure the easier operation of the toggles carrying the paper holdthe cover plate which occurs when pressure is applied at the Wrong spot and to secure the maximum mechanical advantage from the smallest amount of `metal in the booster,

lever.

` With reference tothe drawing,

` "Fig, 1 illustrates; a ring binder mechanism l as `applied to `the bookeover;

Fig. 2 is a vertical, longitudinal section ot the end portionof the device shown in Y Fig. 1;

, upon the flanges cover plate to cause Fig. 3 is a vertical, transverse section taken on the line 3-3 of Fig. 2;V

Fig. 4 is an end view of the device; and

Fig. 5 is a detail showing of the operating or booster lever.` I y i `In `my Patent No. 1,662,303 of March 13, 1928, I illustrated a booster lever ulciumod ofthe base plate in association i With a ring binder system. The curvature `of this lever corresponded substantially to the curvature of cover plate of the binder. The `present invention 1s a substantial `improvement over the form there shown in that l assure the fact that the pressure will be applied at the correct position andv that it Will not beapplied to the deformation and bad applate.

pearanee ofthe to Fi fr. 3, the ring binder With reference `mechanism, generally indicated by 10, comy y prisesa spring backing plate 11 having hook shaped margins 12 and 13` `which form pivots for nthe toggle plates 14 and `15. The toggle plates carry the paper holding prongs 16 and 17. The inner edges of the toggle plates re articulated and retained in position by the double flange studs 18. The operating or booster lever, generally indicated by "19,

25 cut into the connecting arm 23 allow the engagement of the operating lever With the arm 22 is substantially morethan 90.

shaped extension 26 of the spring backing `1ilate11 is benti at right angles to `forni a sto `and lock for the Operating lever.

posed at a considerable angle away romithe horizontal, so.` that the included angle between the connecting arm 23 and the thumb Whentheoperator seeks to open the paper holding prongs, he `presses upon the thumb arms of the operatinglevers of either `end 'of` the loose leaf .holding mechanism. i `Due lto the fact that the cover and the arm together form a transverse notch extending across the apparatus, the thumb isnaturally placed in the notch, and pressure Whenit is `applied is applied by a rolling of the thumb out at the` extremity of the lever 22. Using the sameblank and `exactly the same amount of metal as in my previous booster levers, it `will be noticed that the effective lever `arm causing the :openingof the toggles` is `considerably longer than in designs of ,levers Which extend practically parallelto the coverplate. I am able, thereore, to gain a very considerable mechanical` advantage Without: `increasing the amount of `metal used; Also, the upwardly extending thumbyplate makes a sort of buts indicated at 27, Fig. 2, the cover plate f' efe tress against `which the `thumb U naturally formed and the hooked margins separated i `from the edge of the spring backing plate.

The archingotl the, end of the cover plate for the purpose of forming the thumb guide also materially stiffens the cover plate so much that any usual amount of pressure which might be placed upon it is borne without deformation of the plate.

What I claim, therefore, is: 1. A loose leaf binder mechanism having a transversely curved cover plate longitudinally curved at its ends, a toggle-operating lever normally positioned at an acute angle to the cover and forming with the y "1G longitudinal vcurve of the Cover plate a V-shaped transverse recess serving as `a thumb guide. f.

2. A loose leaf binder mechanism having a spring base member, toggle members piv- 15 oted therein, an arched over plate fitted over said base member and having its end portions downwardly inclined, operating levers for the toggles positioned adjacent to said portions, each lever having an upwardly 20 and backwardly inclined thumb piece'forming with the adjacent end of the cover plate a recess serving as a thumb guide'.

3. In a loose leaf binder, pairs ofpaper holding prongs, a pair of toggle members carrying said prongs and articulated at adjacent edges to form a toggle adapted 'to bend upwardly vto separate, the .pairs of prongs and to bendv downwardly to bring the prongs together, a backing plate beneath the toggle members and having margins against which the toggle members act, an operating lever adapted to act upon the toggle members and the backing plate simultaneously to open the prongs, said lever comprising a transverse portion fulcrumed adjacent to the margins, a thumb piece -projecting upwardly and outwardly from the transverse portion, a lifting arm engaging the toggle members, and an arched cover plate having its end portion inclined upwardly and inwardly from the thumb piece.

4. In a loose leaf binder mechanism having a pair of articulated toggle members carrying paper holding prongs and a sup- 45 porting plate containing the toggle members, an operating lever of relatively great mechanical advantage for the toggle members comprising an intermediate portion fulcrumed in an end portion of the mechanism, a booster arm extending from the intermediate portion and adapted to engage the toggle members, and a relatively long transversely curved thumb arm extending substantially diagonally from the fulcrum axis of the intermediate portion. In testimony whereof I 'aiiiXf my signature.

JAMES C. DAWSON.' 

